The present invention is directed to a package having bottom panel stand-offs. More specifically, the present invention is directed to a package having a plurality of stand-offs or raised portions on the bottom to enhance package stability.
Packages having non-planar bottom walls are known in the art. For example, U.S. Pat. No. 6,027,015 discloses a package having an elevated bottom in which the center portion of the carton bottom wall is elevated from the surface on which the package rests. The package prevents liquids from wicking into the package material along the bottom wall at the raw material edges. Such a package design has proven quite effective for eliminating xe2x80x9csoggyxe2x80x9d package bottoms.
In addition to eliminating wet or soggy package bottoms, it has been found that a secondary benefit of such packages is to enhance the stability of the package. That is, when resting on a grocer""s shelf or dairy case shelf, packages are less likely to lean to one side as a result of a non-planar bottom wall surface. It has been found that the enhanced package stability provides for a much xe2x80x9cneaterxe2x80x9d look in merchandising.
The wide scale acceptance of gable top packaging for foods, generally, is among food packagers and consumers alike. As such, increasing numbers of dry food products are being packaged in these gable top packages. For example, dried soups, snacks and crackers are becoming more popular in these packages. As such, there is an increased desire to improve the aesthetics of these packages for the dry food industry.
Attempts have been made to incorporate the lessons learned or experience of the liquid food packaging industry into the dry foods arena. While much of this experience has been incorporated into dry food packaging, certain types of foods have not fully conformed to these experiences. For example, it has been found that lower density (e.g., lighter) foods have a lesser effect on conforming a package to a square or rectangular shape, than do liquid foods. That is, liquids packaged in these cartons exert forces on the packaging the tend to maintain overcome a slightly off-square or rectangular shape that the package may exhibit as a result of the forming, filling and sealing operation.
Generally, cartons will tend to return to their stored state. In that the cartons are stored in the side-sealed blank form (that is with the side seal formed and in a flat state), the cartons"" natural tendency is to return to this off-rectangular or off-square shape, even after forming, filling and top sealing. This is referred to as xe2x80x9cspring-backxe2x80x9d. Spring-back is generally dependent upon material type and creasing.
Although the forces exerted by higher density product (e.g., liquid foods) better overcome the spring-back effect, less dense product may not. This is true even if the top sealing operation is fully within alignment specifications. As a result, the packages may be unstable and can lean or tilt when merchandised, e.g., on a grocer""s shelf. It has also been found that, while the elevated carton bottom configuration disclosed in the above-noted U.S. Pat. No. 6,027,015 does, in fact, assist in maintaining the squared configuration of the carton, it may not fully do so.
Accordingly, there exists a need for a carton configuration that provides enhanced stability to the carton. Desirably, such a carton functions well with low density (light) food stuffs. Most desirably, such a carton can be manufactured from standard food packaging materials, without the need for carton blank redesign and with minimal changes to the forming, filling and sealing machines.
A package with bottom panel stand-offs includes a plurality of upstanding side walls, each side wall contiguous or sealed to adjacent side wall, a sealed top panel and a sealed bottom panel. The sealed bottom panel has a generally planar portion and three stand-offs formed therein. The three stand-offs are non-coplanar with the generally planar region and define a triangular pattern other than a right angle triangle.
The stand-offs raise the generally planar portion above and spaced from a surface on which the package rests. The package exhibits enhanced stability and functions well with low density (light) food stuffs. The package can be manufactured from standard food packaging materials, without the need for package or carton blank redesign and with minimal changes to the forming, filling and sealing machines.
In one embodiment, one of the stand-offs lies on a bottom panel seal. Alternately, none of the stand-offs lie on the bottom panel seal. A contemplated package is a gable top carton. The stand-offs enhance stability in cartons that otherwise tend to xe2x80x9cspring-back.xe2x80x9d
The stand-offs have a generally rectangular shape. Preferably, the stand-offs are square. First and second stand-offs are formed at first and second adjacent comers of the bottom panel. A third stand-off is formed at about a midpoint of a side opposite of the first and second stand-offs. The triangular pattern formed by the stand-offs is an isosceles triangular pattern. The triangular pattern can be such that a line dividing the triangular pattern defines two back to back, mirror image right triangles.
A bottom forming plate for forming a sealed bottom panel in a carton having bottom panel stand-offs includes a generally planar portion and first, second and third outwardly extending stand-off forming elements. The elements define a triangular pattern other than a right angle triangle. The stand-offs define a plane that is non-coplanar with the generally planar portion.
When the plate is pressed against a carton bottom panel, the first and second stand-off forming elements form first and second and second stand-offs at adjacent comers of the bottom panel and the third stand-off forming element forms a third stand-off at about a midpoint of a side of the carton bottom opposite of the first and second stand-offs. The stand-offs so formed raise the carton bottom above and spaced from a surface on which the package rests.
The stand-off forming elements can have a generally rectangular shape. Preferably, they are square. Most preferably, the plate is formed as a mandrel cap.
A method for forming a stable package includes the steps of forming a carton having four upstanding side walls, each side wall contiguous with or sealed to adjacent side walls and a having a sealed bottom wall. The sealed bottom wall is formed having a generally planar portion. The method further includes forming three and only three bottom panel stand-offs, the stand-offs being first, second and third generally rectangular stand-offs formed in the bottom panel. The stand-offs are formed non-coplanar with the generally planar region and define a triangular pattern other than a right angle triangle.
In forming the stand-offs, the first and second stand-offs are formed at first and second adjacent comers of the bottom panel and the third stand-off is formed at about a midpoint of a side opposite of the first and second stand-offs. The stand-offs raise the generally planar portion above and spaced from a surface on which the package rests.
The method includes filling the carton and sealing a top panel to form a gable.
These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims.